Mat unveils Boston’s open device lab, and provides a beautiful raison d’être while he’s at it:

Websites work everywhere by default, and they stay that way so long as we know how not to break them. That’s what the Open Web means to me: ensuring that entire populations just setting foot on the web for the first time will find it welcoming, regardless of the devices or connections used to get there.

Andy makes a good point here, point out the difference between device testing and design testing:

When I’m designing, it’s incredibly important for me to quickly gain an affinity with how my design feels when I hold it in my hands.

These are not device testing issues, they are design questions and there’s a huge difference between how an interface feels to use on a smartphone size display and whether the HTML, CSS and Javascript actually works on any particular make or model.